Create Action server with multithread executer

#ros2   #python   #action  

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Table of Content

Demo

action server with multithread

import rclpy
import threading
import time
from rclpy.executors import MultiThreadedExecutor
from rclpy.action import ActionServer
from rclpy.node import Node
from rclpy.action.server import ServerGoalHandle

from action_tutorial_interfaces.action import MyAction

TOPIC = "my_action_demo"
PERIOD = 1

class MyActionServer(Node):
    def __init__(self):
        super().__init__('my_action_server')
        self._action_server = ActionServer(
            self,
            MyAction,
            TOPIC,
            self.execute_callback)
        self.__timer = self.create_timer(PERIOD, self.__timer_handler)
        self.__timer
        self.get_logger().info('Start my_action_server version')

    def __timer_handler(self):
        self.get_logger().info("timer thread ->: {}".format(threading.current_thread().ident))


    def execute_callback(self, goal_handle: ServerGoalHandle):
        self.get_logger().info("action thread ->: {}".format(threading.current_thread().ident))
        feedback_msg = MyAction.Feedback()
        for i in range(goal_handle.request.count):
            time.sleep(1)
            self.get_logger().info('current: {}'.format(i))
            feedback_msg.current = i
            goal_handle.publish_feedback(feedback_msg)

        self.get_logger().info('Action ended')
        goal_handle.succeed()

        result = MyAction.Result()
        result.total = i
        return result


def main(args=None):
    rclpy.init(args=args)
    action_server = MyActionServer()
    exec = MultiThreadedExecutor()
    exec.add_node(action_server)
    exec.spin()
    rclpy.spin(action_server)


if __name__ == '__main__':
    main()

Run

run action

ros2 action send_goal -f /my_action_demo action_tutorial_interfaces/action/MyAction "{count: 3}"

server output

[INFO] [1670248402.659192149] [my_action_server]: timer thread ->: 140488007521856
[INFO] [1670248403.657669396] [my_action_server]: timer thread ->: 140487998469696
[INFO] [1670248404.005261426] [my_action_server]: action thread ->: 140487998469696
[INFO] [1670248404.658963720] [my_action_server]: timer thread ->: 140488007521856
[INFO] [1670248405.006998918] [my_action_server]: current: 0
[INFO] [1670248405.658867664] [my_action_server]: timer thread ->: 140487990076992
[INFO] [1670248406.009163793] [my_action_server]: current: 1
[INFO] [1670248406.658945210] [my_action_server]: timer thread ->: 140488015914560
[INFO] [1670248407.011518224] [my_action_server]: current: 2
[INFO] [1670248407.012507114] [my_action_server]: Action ended
[INFO] [1670248407.658774598] [my_action_server]: timer thread ->: 140488015914560